Display device

ABSTRACT

According to one embodiment, a display device includes a first substrate, a second substrate including a first end portion and a second end portion located at a position different from the first end portion, a polymer dispersed liquid crystal layer disposed between the first substrate and the second substrate, a light source device located above the first substrate and disposed along the first end portion, and a light-shielding member disposed on at least a part of the second end portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/130,256, filed on Sep. 13, 2018, and is based upon and claims thebenefit of priority from Japanese Patent Application No. 2017-177073,filed Sep. 14, 2017, the entire contents of which are incorporatedherein by reference.

FIELD

Embodiments described herein relate generally to a display device.

BACKGROUND

Recently, various types of illumination devices employing polymerdispersed liquid crystal (hereinafter called “PDLC”) capable ofswitching a diffusing state of diffusing incident light and atransmitting state of transmitting incident light have been proposed. Alight guide propagates light from a light source. On the light guide,the propagated light may leak at an end portion on a side opposite to alight incident surface.

In contrast, various display devices employing PDLC have been reviewedin recent years.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing a configuration example of a displaydevice DSP according to the embodiments.

FIG. 2 is a perspective view showing the display device DSP shown inFIG. 1.

FIG. 3 is a cross-sectional view showing the display device DSP shown inFIG. 1.

FIG. 4 is an illustration schematically showing liquid crystal layer 30in a transparent state.

FIG. 5 is an illustration schematically showing the liquid crystal layer30 in a scattering state.

FIG. 6 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in a transparent state.

FIG. 7 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in a scattering state.

FIG. 8A is a cross-sectional view showing a first configuration example.

FIG. 8B is a cross-sectional view showing a first modified example ofthe first configuration example.

FIG. 8C is a cross-sectional view showing a second modified example ofthe first configuration example.

FIG. 9 is a cross-sectional view for explanation of an action in a casewhere a functional member 100 is a light-shielding member.

FIG. 10 is a cross-sectional view for explanation of an action in a casewhere the functional member 100 is a reflective member.

FIG. 11 is a cross-sectional view showing a second configurationexample.

FIG. 12A is a cross-sectional view showing a third configurationexample.

FIG. 12B is a cross-sectional view showing a modified example of thethird configuration example.

FIG. 13 is a cross-sectional view showing a fourth configurationexample.

FIG. 14 is an illustration for explanation of diffusibility of a secondfunctional member 120 which is a diffusing member.

FIG. 15 is a cross-sectional view for explanation of an action of thesecond functional member 120 shown in FIG. 14.

FIG. 16 is a plan view for explanation of an action of the secondfunctional member 120 shown in FIG. 14.

FIG. 17 is a plan view showing a first arrangement example.

FIG. 18 is a plan view showing a second arrangement example.

FIG. 19 is a plan view showing a third arrangement example.

FIG. 20 is a plan view showing a fourth arrangement example.

FIG. 21 is a plan view showing a fifth arrangement example.

FIG. 22 is a plan view showing a sixth arrangement example.

FIG. 23 is a plan view showing a seventh arrangement example.

FIG. 24 is a plan view showing an eighth arrangement example.

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided a displaydevice comprising: a first substrate; a second substrate including afirst end portion and a second end portion located at a positiondifferent from the first end portion; a polymer dispersed liquid crystallayer disposed between the first substrate and the second substrate; alight source device located above the first substrate and disposed alongthe first end portion; and a light-shielding member disposed on at leasta part of the second end portion.

According to another embodiment, there is provided a display devicecomprising: a first substrate; a second substrate including a first endportion and a second end portion located at a position different fromthe first end portion; a polymer dispersed liquid crystal layer disposedbetween the first substrate and the second substrate; a light sourcedevice located above the first substrate and disposed along the firstend portion; and a reflective member disposed on at least a part of thesecond end portion.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is a mere example, and arbitrarychange of gist which can be easily conceived by a person of ordinaryskill in the art naturally falls within the inventive scope. To moreclarify the explanations, the drawings may pictorially show width,thickness, shape and the like of each portion as compared with actualembodiments, but they are mere examples and do not restrict theinterpretation of the invention. Furthermore, in the description andfigures of the present application, structural elements having the sameor similar functions will be referred to by the same reference numbersand detailed explanations of them that are considered redundant may beomitted.

FIG. 1 is a plan view showing a configuration example of a displaydevice DSP according to the embodiments. In the drawing, a firstdirection X and a second direction Y intersect each other, and a thirddirection Z intersects the first direction X and the second direction Y.For example, the first direction X, the second direction Y, and thethird direction Z are orthogonal to each other but may intersect at anangle other than ninety degrees. In the present specification, aposition of a distal side of arrow indicating the third direction Z iscalled an upper position while a position of a back side of the arrow iscalled a lower position. According to “a second member above a firstmember” and “a second member below a first member”, the second membermay be in contact with the first member or may be remote from the firstmember. In addition, an observation position at which the display deviceDSP is observed is assumed to be located on the distal side of the arrowindicating the third direction Z, and viewing from the observationposition toward the X-Y plane defined by the first direction X and thesecond direction Y is called a planar view.

In the embodiments, a display device employing polymer dispersed liquidcrystal will be explained as an example of the display device. Thedisplay device DSP comprises a display panel PNL and wiring substratesF1 to F3. In addition, the display device DSP also comprises a lightsource device (not shown).

The display panel PNL comprises a first substrate SUB1, a secondsubstrate SUB2, and a third substrate SUB3. The first substrate SUB1,the second substrate SUB2, and the third substrate SUB3 are arranged inthis order in the third direction Z and overlap in planar view. Thedisplay panel PNL includes a display area DA on which an image isdisplayed and a frame-shaped non-display area NDA surrounding thedisplay area DA. The display area DA is located in an area where thefirst substrate SUB1 and the second substrate SUB2 overlap. The displaypanel PNL includes n scanning lines G (G1 to Gn) and m signal lines S(S1 to Sm), in the display area DA. Each of n and m is a positiveinteger, and n may be equal to or different from m. The scanning lines Gextend in the first direction X and are arranged at intervals in thesecond direction Y. The signal lines S extend in the second direction Yand are arranged at intervals in the first direction X.

The first substrate SUB1 includes end portions E11 and E14 extending inthe first direction X, and end portions E12 and E13 extending in thesecond direction Y. The second substrate SUB2 includes end portions E21and E24 extending in the first direction X, and end portions E22 and E23extending in the second direction Y. The third substrate SUB3 includesend portions E31 and E34 extending in the first direction X, and endportions E32 and E33 extending in the second direction Y.

In the example illustrated in FIG. 1, the end portions E11, E21, and E31overlap but at least one of three end portions may be displaced, inplanar view. Similarly, the end portions E12, E22, and E32 overlap butmay be displaced from one another. Similarly, the end portions E13, E23,and E33 overlap but may be displaced from one another. The end portionsE24 and E34 are located between the end portion E14 and the display areaDA in planar view. The first substrate SUB1 includes an extensionportion Ex between the end portions E14 and E24.

The wiring substrates F1 to F3 are connected to the extension portion Exand arranged in this order in the first direction X. The wiringsubstrate F1 is provided with a gate driver GD1. The wiring substrate F2is provided with a source driver SD. The wiring substrate F3 is providedwith a gate driver GD2. The wiring substrates F1 to F3 may be replacedwith a single wiring substrate.

The signal lines S are drawn to the non-display area NDA and connectedto the source driver SD. The scanning lines G are drawn to thenon-display area NDA and connected to the gate drivers GD1 and/or GD2.In the example illustrated in FIG. 1, odd-numbered scanning lines G aredrawn between the end portion E13 and the display area DA and connectedto the gate driver GD2. In addition, even-numbered scanning lines G aredrawn between the end portion E12 and the display area DA and connectedto the gate driver GD1. The relationship in connection between the gatedrivers GD1 and GD2 and the scanning lines G is not limited to theexample illustrated.

FIG. 2 is a perspective view showing the display device DSP shown inFIG. 1. Illustration of the wiring substrates F1 to F3 is omitted. Alight source device LU is located above the first substrate SUB1 anddisposed along the end portions E24 and E34. The light source device LUcomprises light-emitting elements LS and a wiring substrate F4represented by a dotted line. The light-emitting elements LS arearranged at intervals in the first direction X. Each of thelight-emitting elements LS is connected to the wiring substrate F4. Thelight-emitting elements LS are located between the first substrate SUB1and the wiring substrate F4 in the third direction Z. The light-emittingelements LS are, for example, light-emitting diodes. Each of thelight-emitting elements LS comprises a light-emitting portion EM. Thelight-emitting portion EM faces the end portions E24 and E34. Thelight-emitting portion EM may be in contact with the end portions E24and E34. In addition, an air layer, an optical element, and the like maybe interposed between the light-emitting portion EM and the end portionsE24 and E34. The end portions E24 and E34 correspond to incidenceportions in which the light emitted from the light-emitting portion EMis made incident.

In the present specification, an end portion for incidence at which thelight source device LU is disposed, of the end portions E21 to E24 ofthe second substrate SUB2, corresponds to a first end portion, and theother end portion at a position different from the first end portioncorresponds to a second end portion. An end portion located on thesecond end portion side, of the end portions E11 to E14 of the firstsubstrate SUB1, corresponds to a third end portion. An end portionlocated on the first end portion side, of the end portions E31 to E34 ofthe third substrate SUBS, corresponds to the fourth end portion, and anend portion located on the second end portion side, of the end portionsE31 to E34, corresponds to a fifth end portion.

For example, the end portion E24 corresponds to the first end portion,the end portions E21 to E23 correspond to the second end portions, theend portions E11 to E13 correspond to the third end portions, the endportion E34 corresponds to the fourth end portion, and the end portionsE31 to E33 correspond to the fifth end portions.

The second, third, and fifth end portions may include an end portioncurved in planar view. In contrast, if the second end portions includelinearly extending end portions E21 to E23, the end portion E21 opposedto the first end portion is considered as a first portion, and the endportions E22 and E23 which are adjacent to the first end portion and thefirst portion and which are opposed to each other are considered as asecond portion and a third portion, respectively.

The end portions in the present specification correspond to the sidesurfaces or end surfaces having widths in the third direction Z, in eachof the first substrate SUB1, the second substrate SUB2, and the thirdsubstrate SUBS.

FIG. 3 is a cross-sectional view showing the display device DSP shown inFIG. 1. Main portions alone in the cross-section of the display deviceDSP in a Y-Z plane defined by the second direction Y and the thirddirection Z will be explained here. The display panel PML comprises aliquid crystal layer 30 held between the first substrate SUB1 and thesecond substrate SUB2. The first substrate SUB1 and the second substrateSUB2 are bonded to each other by a seal 40. The third substrate SUB3 isbonded to the second substrate SUB2 by a transparent adhesive ADdisposed across the display area DA and the non-display area NDA.

The first substrate SUB1 comprises a transparent substrate 10, a pixelelectrode 11, an alignment film 12, and the like. The second substrateSUB2 comprises a transparent substrate 20, a common electrode 21, analignment film 22, and the like. The third substrate SUB3 is atransparent substrate. The transparent substrates 10 and 20 and thethird substrate SUB3 are insulating substrates such as glass substratesor plastic substrates. The pixel electrodes 11 and the common electrode21 are formed of, for example, a transparent conductive material such asindium tin oxide (ITO) or indium zinc oxide (IZO). The alignment films12 and 22 may be horizontal alignment films having an alignmentrestriction force approximately parallel to the X-Y plane or may bevertical alignment films having an alignment restriction forceapproximately parallel to the third direction Z. The liquid crystallayer 30 is located in at least the display area DA. The liquid crystallayer 30 is located between the alignment films 12 and 22. Thetransparent state and the scattering state in the liquid crystal layer30 are controlled in response to voltages of the pixel electrodes 11 andthe common electrode 21, as explained with reference to FIG. 4 and FIG.5.

The light-emitting element LS is located above the extension portion Ex.In addition, the light-emitting element LS is located between the wiringsubstrate F1 to F3 and the second substrate SUB2 in the second directionY. The light-emitting element LS emits light from the light-emittingportion EM toward the end portions E24 and E34. The light incident onthe display panel PNL from the end portions E24 and E34 propagates in adirection opposite to the arrow representing the second direction Y asexplained below. The light-emitting element LS may be opposed to the endportions of the first substrate SUB1, the second substrate SUB2, and thethird substrate SUB3, for example, the end portions E11, E21, and E31.

The end portion E11 includes the side surface of the transparentsubstrate 10. The end portion E21 includes a part of the side surface ofthe transparent substrate 20. The end portion E31 includes a part of theside surface of the third substrate SUB3.

FIG. 4 is an illustration schematically showing liquid crystal layer 30in a transparent state. The example illustrated in FIG. 4 corresponds toa state in which no voltage is applied to the liquid crystal layer 30(for example, a state in which a potential difference between the pixelelectrode 11 and the common electrode 21 is approximately zero).

The liquid crystal layer 30 is a polymer dispersed liquid crystal layerincluding polymer 31 which is a polymeric compound and liquid crystalmolecules 32. For example, the polymer 31 is liquid crystal polymer. Thepolymer 31 can be obtained by, for example, polymerizing liquid crystalmonomer in a state of being aligned in a predetermined direction by thealignment restriction force of the alignment films 12 and 22. Forexample, the alignment treatment direction of the alignment films 12 and22 agrees with the first direction X, and the alignment films 12 and 22have the alignment restriction force in the first direction X. For thisreason, the polymer 31 is formed in a streaky shape or a stripe shapeextending in the first direction X. The liquid crystal molecules 32 aredispersed in gaps of the polymer 31 and aligned such that their majoraxis extends in the first direction X.

The polymer 31 and the liquid crystal molecule 32 have opticalanisotropy or refractive anisotropy. The liquid crystal molecule 32 maybe positive liquid crystal molecule having a positive dielectricanisotropy or negative liquid crystal molecule having a negativedielectric anisotropy. The polymer 31 and the liquid crystal molecule 32are different in response performance to the electric field. Theresponse performance of the polymer 31 to the electric field is lowerthan the response performance of the liquid crystal molecule 32 to theelectric field.

An optical axis Ax1 of the polymer 31 and an optical axis Ax2 of theliquid crystal molecule 32 are parallel to each other. In the exampleillustrated in FIG. 4, each of the optical axis Ax1 and the optical axisAx2 is parallel to the first direction X. The polymer 31 and the liquidcrystal molecule 32 have approximately equivalent refractive anisotropy.In other words, ordinary refractive indexes of the polymer 31 and theliquid crystal molecule 32 are approximately equivalent to each other,and extraordinary refractive indexes of the polymer 31 and the liquidcrystal molecule 32 are approximately equivalent to each other. For thisreason, refractive index difference is hardly present between thepolymer 31 and the liquid crystal molecule 32 in all directionsincluding the first direction X, the second direction and the thirddirection Z. For this reason, a light beam L1 incident on the liquidcrystal layer 30 in the third direction Z is transmitted while hardlyscattered in the liquid crystal layer 30. A light beam L2 incident in adirection oblique with respect to the third direction Z is hardlyscattered in the liquid crystal layer 30, either. For this reason, hightransparency can be obtained. The state illustrated in FIG. 4 is calleda transparent state. For example, the light beam L3 corresponds to thelight emitted from the light-emitting element LS shown in FIG. 3, andpropagates in a direction opposite to the direction represented by anarrow of the second direction Y while hardly scattered in the liquidcrystal layer 30.

FIG. 5 is an illustration schematically showing the liquid crystal layer30 in a scattering state. The example illustrated in FIG. 5 correspondsto a state in which a voltage is applied to the liquid crystal layer 30(for example, a state in which a potential difference between the pixelelectrode 13 and the common electrode 21 is higher than or equal to athreshold value). As explained above, the response performance of thepolymer 31 to the electric field is lower than the response performanceof the liquid crystal molecule 32 to the electric field. For example,the alignment direction of the polymer 31 is hardly varied irrespectiveof the presence or absence of the electric field. In contrast, thealignment direction of the liquid crystal molecule 32 is varied inaccordance with the electric field in a state in which a voltage higherthan or equal to the threshold value is applied to the liquid crystallayer 30. In other words, the optical axis Ax1 is substantially parallelto the first direction X while the optical axis Ax2 is oblique to thefirst direction X. If the liquid crystal molecule 32 is positive liquidcrystal molecule, the liquid crystal molecules 32 are aligned such thattheir major axes correspond to the electric field. An electric fieldbetween the pixel electrode 11 and the common electrode 21 is formed inthe third direction Z. For this reason, the liquid crystal molecules 32are aligned such that their major axes or the optical axes Ax2correspond to the third direction Z. In other words, the optical axesAx1 and optical axes Ax2 intersect each other. A large refractive indexdifference is therefore generated between the polymer 31 and the liquidcrystal molecule 32 in all directions including the first direction X,the second direction Y, and the third direction Z. The light beams L1 toL3 incident on the liquid crystal layer 30 are thereby scattered in theliquid crystal layer 30. The state illustrated in FIG. 5 is called ascattering state.

FIG. 6 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in a transparent state. A lightbeam L11 emitted from the light-emitting element LS is made incident onthe display panel PNL from the end portions E24 and E34 to propagatethrough the first substrate SUB1, the liquid crystal layer 30, thesecond substrate SUB2, and the third substrate SUB3. Since the liquidcrystal layer 30 is in the transparent state, the light beam L11 ishardly scattered in the liquid crystal layer 30, and hardly leaks from alower surface 10B of the transparent substrate 10 or an upper surface 3Tof the third substrate SUB3.

An external light beam L12 incident on the display panel PNL istransmitted and hardly scattered in the liquid crystal layer 30. Inother words, the external light beam L12 incident on the display panelPNL from the lower surface 10B is transmitted through the upper surface30T, and the external light beam L12 incident on the display panel PNLfrom the upper surface 30T is transmitted through the lower surface 10B.For this reason, the user can visually recognize a background on thelower surface 10B side through the display panel PNL when observing thedisplay panel PNL from the upper surface 30T side. Similarly, the usercan visually recognize a background on the upper surface 3T side throughthe display panel PNL when observing the display panel PNL from thelower surface 10B side.

FIG. 7 is a cross-sectional view showing the display panel PNL in a casewhere the liquid crystal layer 30 is in a scattering state. A light beamL21 emitted from the light-emitting element LS is made incident on thedisplay panel PNL from the end portions E24 and E34 to propagate throughthe display panel PNL. In the example illustrated in FIG. 7, since theliquid crystal layer 30 overlapping a pixel electrode 11A is in thetransparent state, the light beam L21 is hardly scattered in an area ofthe liquid crystal layer 30 which overlaps the pixel electrode 11A. Incontrast, the liquid crystal layer 30 overlapping a pixel electrode 11Bis in the scattering state. For this reason, the light beam L21 isscattered in an area which overlaps the pixel electrode 11B in theliquid crystal layer 30. A scattered light beam L211 which is a part ofthe light beam L21 is transmitted through the upper surface 3T, ascattered light beam L212 which is another part of the light beam L21 istransmitted through the lower surface 10B, and the other scatter lightbeam propagates through the inside of the display panel PNL.

In the area which overlaps the pixel electrode 11A, an external lightbeam L22 incident on the display panel PNL is transmitted and hardlyscattered in the liquid crystal layer 30, similarly to the externallight beam L12 shown in FIG. 6. In the area which overlaps the pixelelectrode 11B, an external light beam L23 incident from the lowersurface 10B is scattered in the liquid crystal layer 30 and a light beamL231 which is a part of the external light beam L23 is transmittedthrough the upper surface 3T. In addition, an external light beam L24incident from the upper surface 3T is scattered in the liquid crystallayer 30 and a light beam L241 which is a part of the external lightbeam L24 is transmitted through the lower surface 10B. For this reason,the user can visually recognize a color of the light beam L21 in thearea overlapping the pixel electrode 11B when observing the displaypanel PNL from the upper surface 3T side. In addition, since the lightbeam L231 of the external light beam L23 is transmitted through thedisplay panel PNL, the user can also visually recognize the backgroundon the lower surface 10B side through the display panel PNL. Similarly,the user can visually recognize a color of the light beam L21 in thearea overlapping the pixel electrode 11B when observing the displaypanel PNL from the lower surface 10B side. In addition, since the lightbeam L241 of the external light beam L24 is transmitted through thedisplay panel PNL, the user can also visually recognize the backgroundon the upper surface 3T side through the display panel PNL. In the areaoverlapping the pixel electrode 11A, the color of the light beam L21 canhardly be recognized visually and the user can visually recognize thebackground through the display panel PNL since the liquid crystal layer30 is in the transparent state.

Incidentally, the light beam L11 shown in FIG. 6 often leaks to theoutside after reaching the end portion E31. Similarly, the light havingpropagated through the display panel PNL may also leak on the endportions E11 and E21. In the display device DSP having the end portionsE11, E21, and E31 exposed, the occurrence of undesired light leakage maycause an impression of the appearance of the display device DSP to bedegraded. In addition, the proximity to the end portion E21 is locatedremote from the light source device LU and tends to have a lowerluminance as compared with the proximity to the end portion E24, whichis the incidence portion. This difference in luminance between theproximity to the end portion E21 and the proximity to the end portionE24 may cause the display quality to be degraded.

Thus, first to fourth configuration examples will be hereinafterdisclosed in the present specification to suppress undesired lightleakage.

First Configuration Example

FIG. 8A is a cross-sectional view showing a first configuration example.The display device DSP comprises a functional member 100 having anoptical function. The functional member 100 is, for example, alight-shielding member, a reflective member, a diffusing member, or thelike. The functional member 100 is disposed on the end portion E21. Inthe example illustrated in FIG. 8A, the functional member 100 is incontact with the end portion E21. The functional member 100 may be athin film formed directly on the end portion E21 or a thin film bondedto the end portion E21 by an adhesive.

The functional member 100 is also disposed on the end portions E11 andE31. In the example illustrated in FIG. 8A, the functional member 100 isalso in contact with the end portions E11 and E31. The functional member100 may be disposed on the end portions E11, E21, and E31 separately orintegrally. In the example illustrated in FIG. 8A, the end portions E11,E21, and E31 are located on the same plane parallel to X-Z plane definedby the first direction X and the third direction Z. In other words, theend portion E21 is located just above the end portion E11, and the endportion E31 is located just above the end portion E21. In this example,the single functional member 100 is disposed on the end portions E11,E21, and E31.

FIG. 8B is a cross-sectional view showing a first modified example ofthe first configuration example. The third substrate SUB3 is disposedbelow the first substrate SUB1 and bonded to the first substrate SUB1.In the first modified example, too, the functional member 100 isdisposed on the end portions E11, E21, and E31.

FIG. 8C is a cross-sectional view showing a second modified example ofthe first configuration example. The second modified example isdifferent from the first modified example with respect to a feature thatthe end portions E34, E14, and E24 are arranged in the third direction Zin this order and the end portions are located on the same planesubstantially parallel to X-Z plane. The end portions E34, E14, and E24are opposed to the light-emitting element LS in the second direction Y.

FIG. 9 is a cross-sectional view for explanation of an action in a casewhere a functional member 100 is a light-shielding member. Thelight-shielding member is formed of, for example, a resin materialcolored in block or a light-shielding metal material. A light beam L31emitted from the light-emitting element LS is made incident from the endportions E24 and E34 to propagate through the first substrate SUB1, thesecond substrate SUB2, and the third substrate SUB3. The light beam L31having reached the end portion E21 is blocked by the functional member100. The light beam L31 having reached the end portions E11 and E31 isalso blocked by the functional member 100. For this reason, undesiredlight leakage can be suppressed. Degradation in impression of theappearance can be therefore suppressed in the display device DSP.

FIG. 10 is a cross-sectional view for explanation of an action in a casewhere the functional member 100 is a reflective member. The reflectivemember is formed of, for example, a metal material having a highreflectance such as aluminum, silver, or titanium. A light beam L31emitted from the light-emitting element LS is made incident from the endportions E24 and E34 to propagate through the first substrate SUB1, thesecond substrate SUB2, and the third substrate SUB3. The light beam L31having reached the end portion E21 is reflected to the light-emittingelement LS side by the functional member 100. The light beam L31 havingreached the end portions E11 and E31 is also reflected by the functionalmember 100. For this reason, undesired light leakage can be suppressedand the light having reached the end portion E21 side opposite to thelight-emitting element LS can be reused. Degradation in the luminance onthe end portion E21 side can be therefore suppressed. Thus, thebrightness difference between the end portion E24 side close to thelight-emitting element LS and the end portion 521 side remote from thelight-emitting element LS can be reduced and the degradation in displayquality can be suppressed.

In the example illustrated in FIG. 10, the end portion E24 correspondsto the first portion, the end portion E21 corresponds to the second endportion, the end portion E11 corresponds to the third end portion, theend portion E34 corresponds to the fourth end portion, and the endportion E31 corresponds to the fifth end portion.

Second Configuration Example

FIG. 11 is a cross-sectional view showing a second configurationexample. The second configuration example is different from the firstconfiguration example with respect to a feature that the functionalmember 100 is also disposed on the lower surface 10B and the uppersurface 3T of the non-display area NDA. The single functional member 100is disposed on the end portions E11, E21, and E31, a portion exceedingthe end portion E11 is bent and disposed on the lower surface 10B, and aportion exceeding the end portion E31 is bent and disposed on the uppersurface 3T. The functional member 100 is in contact with each of the endportions E11, E21, and E31, the lower surface 10B, and the upper surface3T. The functional member 100 may be a light-shielding member or areflective member as explained above.

In the second configuration example, too, the same advantages as thoseof the first configuration example can be obtained. In addition,undesired light leakage from the lower surface 10B and the upper surface3T in the non-display area NDA can be suppressed.

Third Configuration Example

FIG. 12A is a cross-sectional view showing a third configurationexample. The third configuration example is different from the firstconfiguration example with respect to a feature of comprising aplurality of functional members 100A and 100B. In the exampleillustrated in FIG. 12A, the end portion E21 is located just above theend portion E11, while the end portions E31 is not located just abovethe end portion E21 but displaced from the end portion E21 in the seconddirection Y. The functional member 100A is disposed on the end portionsE11 and E21, and the functional member 100B is disposed on the endportion E31. The functional members 100A and 100B may be light-shieldingmembers or reflective members as explained above. In addition, thefunctional members may be separated in accordance with the number of theend portions arranged in the third direction Z or the functional membersmay be disposed on the end portions E11, E21, and E31, respectively.

In the third configuration example, too, the same advantages as those ofthe first configuration example can be obtained. In addition, if atleast one of the end portions E11, E21, and E31 is displaced, thefunctional members 100A and 100B are hardly peeled off from the endportions E11, E21, and E31. For this reason, if the functional members100A and 100B are reflective members, degradation in display qualitywhich results from non-uniformity in reflected light can be suppressed.

FIG. 12B is a cross-sectional view showing a modified example. Thesingle functional member 100 is disposed on the end portions E11, E21,and E31, bent between the end portions E21 and E31, and disposed on anupper surface 2T of the second substrate SUB2. The functional member 100is in contact with the upper surface 2T at a position between the endportions E21 and E31. The functional member 100 may be a light-shieldingmember or a reflective member as explained above.

Fourth Configuration Example

FIG. 13 is a cross-sectional view showing a fourth configurationexample. The fourth configuration example is different from the firstconfiguration example with respect to a feature of comprising a firstfunctional member 110 and a second functional member 120 having afunction different from the first functional member 110. In the exampleillustrated in FIG. 13, the second functional member 120 is in contactwith the end portion E21, and the first functional member 110 is incontact with the second functional member 120. Not only the secondfunctional member 120, but also the other functional members may bedisposed between the first functional member 110 and the end portionE21. The first functional member 110 may be a thin film formed directlyon the end portion E21 and the second functional member 120 may be athin film formed directly on the first functional member 110, or thefirst functional member 110 may be a thin film and the second functionalmember 120 may be an adhesive to bond the first functional member 110 tothe end portion E21. For example, the first functional member 110 is areflective member, and the second functional member 120 is a diffusingmember.

The stacked layer body of the first functional member 110 and the secondfunctional member 120 is also disposed on the end portions E11 and E31.The second functional member 120 is in contact with each of the endportions E11 and E31. In an example in which the end portion E21 islocated just above the end portion E11, and the end portion E31 islocated just above the end portion E21, the single first functionalmember 110 and the single second functional member 120 overlap in thesecond direction Y, and the first functional member 110 and the secondfunctional member 120 are disposed on the end portions E11, E21, andE31.

The first functional member 110 and the second functional member 120 mayextend to the lower surface 10B and the upper surface 3T, similarly tothe second configuration example. In addition, the first functionalmember 110 and the second functional member 120 may be separated to bedisposed on the respective end portions, similarly to the thirdconfiguration example.

FIG. 14 is an illustration for explanation of diffusibility of a secondfunctional member 120 which is a diffusing member. The second functionalmember 120 diffuses the light incident in the second direction Y intothe X-Z plane. The second functional member 120 explained here is ananisotropically diffusing member having diffusibility Dx in the firstdirection X larger than diffusibility Dz in the third direction Z. Asexplained above, the longitudinal direction of the end portion E21 isparallel to the first direction X, and the thickness direction of theend portion E21 is parallel to the third direction Z. In other words,the light passing through the second functional member 120 is diffusedmore largely in the longitudinal direction of the end portion E21 thanin the thickness direction of the end portion E21.

FIG. 15 is a cross-sectional view for explanation of an action of thesecond functional member 120 shown in FIG. 14. Since the secondfunctional member 120 has smaller diffusibility DZ, the diffusion in thethird direction Z, of the light reflected by the first functional member110 can be suppressed. For this reason, leakage of the reflected lightfrom the lower surface 10B and the upper surface 3T can be suppressed.

FIG. 16 is a plan view for explanation of an action of the secondfunctional member 120 shown in FIG. 14. Since the second functionalmember 120 has larger diffusibility Dx, the light reflected by the firstfunctional member 110 is diffused in the first direction X and theluminance of the reflected light can be uniformed at positions close tothe end portion E21 and the like. In addition, even if the end portionE21 and the like have cracks or fine unevenness, the luminance of thereflected light can be uniformed by the diffusing effect of the secondfunctional member 120.

Arrangement Example

An arrangement example of various functional members will be explainedbelow. Each of arrangement examples explained below can be employed inany one of the first to fourth configuration examples explained above.

FIG. 17 is a plan view showing a first arrangement example. The singlefunctional member 100 is disposed on the only end portions E11, E21, andE31 on the side opposite to the end portions E24 and E34, which are theincidence portions. The functional member 100 is a light-shieldingmember or a reflective member. If the functional member 100 is alight-shielding member, the light leakage at the end portion E21 can besuppressed. If the functional member 100 is a reflective member, thelight leakage at the end portion E21 can be suppressed and thedegradation in luminance on the end portion E21 side can also besuppressed.

FIG. 18 is a plan view showing a second arrangement example. The secondarrangement example is different from the fifth arrangement example withrespect to a feature of comprising functional members 101 to 103. Thefunctional member 101 is disposed on the end portions E11, E21, and E31extending in the first direction X. The functional member 102 isdisposed on the end portions E12, E22, and E32 extending in the seconddirection Y. The functional member 103 is disposed on end portions E13,E23, and E33 extending in the second direction Y. Each of the functionalmembers 101 to 103 is formed independently. The functional members 101to 103 are light-shielding members or reflective members.

All of the functional members 101 to 103 may be light-shielding membersor reflective members. In addition, a combination of the functionalmember 101 which is a reflective member and the functional members 102and 103 which are light-shielding members, a combination of thefunctional member 101 which is a light-shielding member and thefunctional members 102 and 103 which are reflective members, and thelike can be applied.

In the second arrangement example, too, the same advantages as those ofthe first arrangement example can be obtained. In addition, if thefunctional members 102 and 103 are light-shielding members, thefunctional members 102 and 103 can also suppress the light leakage atthe end portions E22 and E23. If the functional members 102 and 103 arereflective members, the functional members 102 and 103 can suppress thelight leakage at the end portions E22 and E23 and the degradation inluminance on the end portion E22 side and the end portion E23 side.

FIG. 19 is a plan view showing a third arrangement example. The thirdarrangement example is different from the first arrangement example withrespect to a feature that the single functional member 100 is disposedalong three sides except the incidence portions. The functional member100 is disposed on the end portions E11, E21, and E31, disposed on theend portions E12, E22, and E32, and disposed on the end portions E13,E23, and E33. The functional member 100 is a light-shielding member or areflective member.

In the third arrangement example, too, the same advantages as those ofthe second arrangement example can be obtained.

FIG. 20 is a plan view showing a fourth arrangement example. The fourtharrangement example is different from the first arrangement example withrespect to a feature of comprising a first functional member 111 and asecond functional member 121 different in function. The secondfunctional member 121 is in contact with the end portions E11, E21, andE31. The first functional member 111 overlaps the second functionalmember 121. For example, the first functional member 111 is a reflectivemember, and the second functional member 121 is a diffusing member.

In the fourth arrangement example, the light leakage at the end portionE21 can be suppressed, the degradation in luminance on the end portionE21 side can be suppressed, and the luminance can be uniformed.

FIG. 21 is a plan view showing a fifth arrangement example. The fiftharrangement example is different from the fourth arrangement examplewith respect to a feature of comprising first functional members 112 and113 besides the first functional member 111. The first functional member112 is in contact with the end portions E12, E22, and E32. The firstfunctional member 113 is in contact with the end portions E13, E23, andE33. For example, the first functional members 111 to 113 are reflectivemembers, and the second functional member 121 is a diffusing member.

In the fifth arrangement example, too, the same advantages as those ofthe fourth arrangement example can be obtained. In addition, degradationin the luminance on the end portion E22 side and the end portion E23side can be suppressed.

FIG. 22 is a plan view showing a sixth arrangement example. The sixtharrangement example is different from the fifth arrangement example withrespect to a feature of further comprising second functional members 122and 123. The second functional member 122 is in contact with the endportions E12, E22, and E32. The first functional member 112 overlaps thesecond functional member 122. The second functional member 123 is incontact with the end portions E13, E23, and E33. The first functionalmember 113 overlaps the second functional member 123. For example, thefirst functional members 111 to 113 are reflective members, and thesecond functional members 121 to 123 are diffusing members.

In the fifth arrangement example, too, the same advantages as those ofthe fourth arrangement example can be obtained. In addition, degradationin the luminance on the end portion E22 side and the end portion E23side can be suppressed, and the luminance can be uniformed.

FIG. 23 is a plan view showing a seventh arrangement example. Theseventh arrangement example is different from the above-explainedarrangement examples with respect to a feature of comprising lightsource devices LU1 and LU2. The first substrate SUB1 comprises extensionportions Ex1 and Ex2 further extending in the second direction Y thanthe second substrate SUB2 and the third substrate SUB3. The light sourcedevice LU1 is located above the extension portion Ex1, and the lightsource device LU2 is located above the extension portion Ex2.

The light source device LU1 is disposed along the end portions E24 andE34. The light source device LU1 comprises light-emitting elements LS1arranged at intervals in the first direction X, and a wiring substrateF4 to which the light-emitting elements LS1 are connected. For example,two light-emitting elements LS1 arranged in the first direction Xcorrespond to a first light-emitting element and a second light-emittingelement, respectively. A second functional member 124 located betweentwo light-emitting elements LS1 is disposed on the end portions E24 andE34, and the first functional member 114 overlaps the second functionalmember 124.

The light source device LU2 is disposed along the end portions E21 andE31. The light source device LU2 comprises light-emitting elements LS2arranged at intervals in the first direction X, and a wiring substrateF5 to which the light-emitting elements LS2 are connected. A secondfunctional member 121 located between two light-emitting elements LS2 isdisposed on the end portions E21 and E31, and the first functionalmember 111 overlaps the second functional member 121. The firstfunctional members 111 and 114 are reflective members, and the secondfunctional members 121 and 124 are diffusing members.

The light emitted from the light-emitting elements LS1 is made incidentfrom the end portions E24 and E34 to propagate toward the end portionsE21 and E31. The light having reached the end portions E21 and E31 isdiffused by the second functional member 121 and reflected by the firstfunctional member 111. Similarly, the light emitted from thelight-emitting elements LS2 is made incident from the end portions E21and E31 to propagate toward the end portions E24 and E34. The lighthaving reached the end portions E24 and E34 is diffused by the secondfunctional member 124 and reflected by the first functional member 114.

According to the seventh arrangement example, degradation in theluminance on the end portion E21 side and the end portion E24 side canbe suppressed, and the luminance can be uniformed.

FIG. 24 is a plan view showing an eighth arrangement example. The eightharrangement example is different from the above-explained arrangementexamples with respect to a feature that the first substrate SUB1, thesecond substrate SUB2, and the third substrate SUB3 have differentshapes. The first substrate SUB1 includes an end portion E15 extendingin the first direction X, and an end portion E16 having at least a partformed in a curved shape in planar view. In the example illustrated inFIG. 24, the first substrate SUB1 is formed in an ellipsoidal shape (ora track shape) in planar view. The first substrate SUB1, the secondsubstrate SUB2 and the third substrate SUB3 are formed in substantiallythe same shape. The second substrate SUB2 includes an end portion E25located on the end portion E15 side and an end portion E26 located onthe end portion E16 side. The third substrate SUB3 includes an endportion E35 located on the end portion E15 side and an end portion E36located on the end portion E16 side.

The light source device LU is disposed along the end portions E15, E25,and E35. The second functional member 120 is disposed on the endportions E16, E26, and E36. The first functional member 110 overlaps thesecond functional member 120.

According to the eighth arrangement example, degradation in theluminance on the end portion E26 side can be suppressed, and theluminance can be uniformed.

As explained above, a display device capable of suppressing theundesired light leakage can be provided by the present embodiments.

The present invention is not limited to the embodiments described abovebut the constituent elements of the invention can be modified in variousmanners without departing from the spirit and scope of the invention.Various aspects of the invention can also be extracted from anyappropriate combination of a plurality of constituent elements disclosedin the embodiments. For example, some structural elements may be deletedfrom the entire structural elements in the embodiments. Furthermore,structural elements described in different embodiments may be combinedsuitably.

In the above-explained embodiments, the configuration examples employingthe polymer dispersed liquid crystal for the display panel PNL have beenexplained, but the configuration examples may be employed in anillumination device combined with a transmissive display panel or areflective display panel. According to the illumination device, thescattering state and the transparent state can be changed on not onlythe entire surface of the display area DA, but also a partial surface ofthe display area DA. In addition, loss resulting from undesiredscattering and undesired absorption can be reduced and the efficiency ofuse of the light can be improved, by employing the above-explainedconfiguration examples.

Examples of the display device which can be obtained from theconfigurations described in the present specification will behereinafter explained.

(1)

A display device, comprising:

a first substrate;

a second substrate including a first end portion and a second endportion located at a position different from the first end portion;

a polymer dispersed liquid crystal layer disposed between the firstsubstrate and the second substrate;

a light source device located above the first substrate and disposedalong the first end portion; and

a light-shielding member disposed on at least a part of the second endportion.

(2)

The display device according to (1), wherein

the first substrate includes a third end portion located on the secondend portion side, and

the light-shielding member is disposed on at least a part of the thirdend portion.

(3)

The display device according to (1) or (2), further comprising:

a third substrate,

wherein

the second substrate is located between the first substrate and thethird substrate,

the third substrate includes a fourth end portion located on the firstend portion side and a fifth end portion located on the second endportion side,

the light source device is disposed along the fourth end portion, and

the light-shielding member is disposed on at least a part of the fifthend portion.

(4)

A display device, comprising:

a first substrate;

a second substrate including a first end portion and a second endportion located at a position different from the first end portion;

a polymer dispersed liquid crystal layer disposed between the firstsubstrate and the second substrate;

a light source device located above the first substrate and disposedalong the first end portion; and

a reflective member disposed on at least a part of the second endportion.

(5)

The display device according to (4), further comprising:

a diffusing member located between the second end portion and thereflective member.

(6)

The display device according to (5), wherein

the diffusing member is an anisotropically diffusing member.

(7)

The display device according to any one of (4) to (6), wherein

the first substrate includes a third end portion located on the secondend portion side, and

the reflective member is disposed on at least a part of the third endportion.

(8)

The display device according to any one of (4) to (7), furthercomprising:

a third substrate,

wherein

the second substrate is located between the first substrate and thethird substrate,

the third substrate includes a fourth end portion located on the firstend portion side and a fifth end portion located on the second endportion side,

the light source device is disposed along the fourth end portion, and

the reflective member is disposed on at least a part of the fifth endportion.

(9)

The display device according to any one of (4) to (8), wherein

the second end portion includes a first portion opposed to the first endportion, and a second portion and a third portion which are opposed toeach other,

the second portion and the third portion are adjacent to the first endportion and the first portion, respectively,

the reflective member and the diffusing member are disposed on the firstportion, and

the diffusing member is in contact with the first portion.

(10)

The display device according to (9), wherein

the reflective member and the diffusing member are disposed on thesecond portion and the third portion, and

the diffusing member is in contact with each of the second portion andthe third portion.

(11)

The display device according to (9), wherein

the reflective member is disposed on the second portion and the thirdportion, and

the reflective member is in contact with each of the second portion andthe third portion.

(12)

The display device according to (4), wherein

the light source device comprises:

a first light-emitting element and a second light-emitting element; and

a diffusing member,

the diffusing member is located between the first light-emitting elementand the second light-emitting element, at the first end portion.

(13)

The display device according to any one of (1) to (12), wherein

the polymer dispersed liquid crystal layer includes a polymer formed ofa polymeric material and liquid crystal molecules dispersed in thepolymer.

(14)

The display device according to any one of (1) to (13), wherein

the first substrate comprises a pixel electrode,

the second substrate comprises a common electrode, and

a transparent state and a scattering state of the polymer dispersedliquid crystal layer are controlled in accordance with voltages appliedto the pixel electrode and the common electrode.

(15)

The display device according to (8), wherein

light from the light source device is made incident on the first endportion of the second substrate, and the fourth end portion of the thirdsubstrate.

What is claimed is:
 1. A display device, comprising: a first substrate;a second substrate including a first end portion and a second endportion located at a position different from the first end portion; athird substrate including a fourth end portion located on a first endportion side and a fifth end portion located on a second end portionside, the second substrate being between the first substrate and thethird substrate, a polymer dispersed liquid crystal layer disposedbetween the first substrate and the second substrate; a light sourcedevice located above the first substrate and disposed along the firstend portion and the fourth end portion; and a light-shielding memberdisposed on at least a part of the second end portion and at least apart of the fifth end portion, wherein the fifth end portion is locatedcloser to the light source device than the second end portion, and asurface of the second substrate between the second end portion and thefifth end portion, in the sectional view, is not covered by thelight-shielding member.
 2. The display device according to claim 1,wherein light from the light source device is made incident on the firstend portion of the second substrate, and the fourth end portion of thethird substrate.
 3. The display device according to claim 1, wherein thefirst substrate comprises a pixel electrode, the second substratecomprises a common electrode, and a transparent state and a scatteringstate of the polymer dispersed liquid crystal layer are controlled inaccordance with voltages applied to the pixel electrode and the commonelectrode.
 4. The display device according to claim 1, wherein thesecond end portion includes a first portion opposed to the first endportion, and a second portion and a third portion which are opposed toeach other, both the second portion and the third portion intersect thefirst end portion and the first portion, and the light-shielding memberis disposed on the first portion, and is not disposed on the second andthird portions.
 5. The display device according to claim 1, wherein thesecond end portion includes a first portion opposed to the first endportion, and a second portion and a third portion which are opposed toeach other, both the second portion and the third portion intersect thefirst end portion and the first portion, and the light-shielding memberis disposed on the second and third portions, and is not disposed on thefirst portions.
 6. A display device, comprising: a first substrate; asecond substrate including a first end portion and a second end portionlocated at a position different from the first end portion; a thirdsubstrate including a fourth end portion located on a first end portionside and a fifth end portion located on a second end portion side, thesecond substrate being between the first substrate and the thirdsubstrate, a polymer dispersed liquid crystal layer disposed between thefirst substrate and the second substrate; a light source device locatedabove the first substrate and disposed along the first end portion andthe fourth end portion; and a light-shielding member or a reflectivemember disposed on at least a part of the second end portion and atleast a part of the fifth end portion, wherein the fifth end portion islocated closer to the light source device than the second end portion,and a surface of the second substrate between the second end portion andthe fifth end portion, in the sectional view, is covered by thelight-shielding member or the reflective member.
 7. The display deviceaccording to claim 6, wherein light from the light source device is madeincident on the first end portion of the second substrate, and thefourth end portion of the third substrate.
 8. The display deviceaccording to claim 6, wherein the first substrate comprises a pixelelectrode, the second substrate comprises a common electrode, and atransparent state and a scattering state of the polymer dispersed liquidcrystal layer are controlled in accordance with voltages applied to thepixel electrode and the common electrode.